Download App

Dual Nature of Radiation and Matter — Physics STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 SciencePhysicsDual Nature of Radiation and Matter3 Marks
Question
Write Einstein's photoelectric equation. State clearly how this equation is obtained using the photon picture of electromagnetic radiation.
Write the three salient features observed in photoelectric effect which can be explained using this equation.
✓

Answer

$\text{h} \text{v }= \Phi_{o} + \text{k}_\text{max}$
Energy $(h),$ carried by a photon of frequency $v,$ is absorbed $($by the electrons on the surface.$)$ to:
  1. Overcome the work function of metal $(\Phi_{o}).$
  2. Impart maximum kinetic energy to the emitted electron $(K_{max})$
$\therefore\text{h }\text{v} = \Phi_{o} + \text{k}_{max}$
Three salient features:
  1. Cut $-$ off potential of the emitted electrons is proportional to $v$.
  2. maximum kinetic energy is independent of the intensity of incident radiations.
  3. Photoelectric emission of electrons is possible only when $\text{V} > \text{V}_{0} - \frac{\phi_{o}}{\text{h}}.$
  4. Emission of electrons is instantaneous.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "3 Marks Question" from Dual Nature of Radiation and Matter→Dual Nature of Radiation and Matter — all question types→Physics STD 12 Science question papers→Rajasthan Board STD 12 Science question papers→Rajasthan Board question paper generator→

Similar questions

The figure shows two identical rectangular loops (1) and (2) placed on a table along with a straight long current carrying conductor between them.
i. What will be the directions of the induced current in the loops when they are pulled away from the conductor with same velocity v?
ii. Will the emf induced in the two loops be equal?
Image
→
What is an unpolarized light? Explain with the help of suitable ray diagram how an unpolarized light can be polarized by reflection from a transparent medium. Write the expression for Brewster angle in terms of the refractive index of denser medium.
→
A parallel$-$plate capacitor with plate area $20\ cm^2$ and plate separation $1.0\ mm$ is connected to a battery. The resistance of the circuit is $10\text{k}\Omega.$ Find the time constant of the circuit.
→
Find the acceleration of a particle placed on the surface of the earth at the equator due to earth's rotation. The diameter of earth = 12800km and it takes 24 hours for the earth to complete one revolution about its axis.
→
An electric field of $20NC^{-1}$ exists along the $x-$axis in space. Calculate the potential difference $V_B - V_A$ where the points $A$ and $B$ are given by,
  1. $A = (0, 0); B = (4m, 2m)$
  2. $A = (4m, 2m); B = (6m, 5m)$
  3. $A = (0, 0); B = (6m, 5m)$
Do you find any relation between the answers of parts $(a), (b) $and $(c)?$
→
  1. Write three characteristic properties of nuclear force.
  2. Draw a plot of potential energy of a pair of nucleons as a function of their separation. Write two important conclusions that can be drawn from the graph.
→
Three charges are arranged on the vertices of an equilateral triangle as shown in figure. Find the dipole moment of the combination.
→
$A$ charge of $+2.0 \times 10^{-8}C$ is placed on the positive plate and a charge of $-1.0 \times 10^{-8}C$ on the negative plate of a parallel $-$ plate capacitor of capacitance $1.2\times10^{-3}\mu\text{F}.$ Calculate the potential difference developed between the plates.
→
How will establish displacement current of 6 A between the plates of a capacitor of capacitance $6 \mu F$ ?
→
The following table gives the output of a two input logic gate.
  1. Identify the logic gate and draw its logic symbol.
  2. If the output of this gate is fed as input to a NOT gate, name the new logic gate so formed.
A
B
Y
0
0
1
1
0
1
0
1
1
1
1
0
→